Genetic parameters and trend for goat milk production in Brazil

[摘要] Dairy goat production in Brazil, although firmly established since a few decades, has proved to be totally dependent on foreign countries for genetic improvement. Most herds presently producing are based on imported animals, and genetic refreshment is obtained through imported semen. No information is available on the genetic values and their evaluation along the years. In this paper, heritability and repeatability estimates, obtained through REML, are reported for milk yield. The values were 0.21557 and 0.21564, respectively. The BLUP method with animal model was used to predict genetic values. The annual change in genetic trend, estimated by means of a quadratic model, was -0.8109 kg/year2, which indicates a slowdown in genetic gain. The Pearson correlation between buck genetic values estimated by means of the most likely production of daughters and least squares and those estimated through BLUP and mixed model equations was 0.5751; the Spearman correlation between buck ranks obtained by both methods was 0.5813.

[学科分类] 兽医学

[关键词] heritability;repeatability;genetic values  IntroduçãoA caprinocultura leiteira no Brasil;nas últimas três décadas;vem se consolidando como atividade rentável;despertando o interesse de muitos produtores rurais